It’s oil from your skin. The pretty heat colors on the stainless steel are a result of oxidization of the metal, which reaches different depths as it gets hotter - but if the metal is heated rapidly enough, or to a low enough temperature the steel will begin to discolour before the oils burn off. Since the area with skin oil on it has a barrier between the metal and the oxygen (the oil), the outline of the hand is prevented from gaining a color and thus it shows up like this.
It’s neat to see in person, with a light touch you can easily see the distinct patterns of a person’s fingerprints outlined in some really pretty colors.
You got a solid explanation but I’ll add this; No one could press their hand on that hot engine long enough to make a perfect print like that. Somebody did it for giggles.
Hopimg that’s glove residue and not skin :(
It’s oil from your skin. The pretty heat colors on the stainless steel are a result of oxidization of the metal, which reaches different depths as it gets hotter - but if the metal is heated rapidly enough, or to a low enough temperature the steel will begin to discolour before the oils burn off. Since the area with skin oil on it has a barrier between the metal and the oxygen (the oil), the outline of the hand is prevented from gaining a color and thus it shows up like this.
Ah ok that was interesting to learn and also that it’s just oils from skin
It’s neat to see in person, with a light touch you can easily see the distinct patterns of a person’s fingerprints outlined in some really pretty colors.
Or maybe it’s an oily handprint that was left when it was cold and then the oil affected how the metal oxidized when it got hot.
You got a solid explanation but I’ll add this; No one could press their hand on that hot engine long enough to make a perfect print like that. Somebody did it for giggles.